Storage battery internal resistance detection circuit and method

Abstract

The invention discloses a storage battery internal resistance detection circuit, wherein the main controller and the constant-current discharge circuit are electrically connected. The constant-currentdischarge circuit comprises a power supply, a first comparator and an MOS tube. The controller at least outputs two analog quantity signals. The analog quantity signal output end of the main controller is connected with the positive phase input end of the first comparator; wherein the sampling signal output end of the main controller is connected with the inverting input end of the first comparator, the voltage of the non-inverting input end of the first comparator is equal to the voltage of the inverting input end of the first comparator, the output end of the first comparator is connected to the grid electrode of the MOS tube, the drain electrode of the MOS tube is connected with a power supply, and the source electrode of the MOS tube is grounded. The main controller outputs differentanalog quantity signals in a matching manner according to the actual sampling signal data, the voltage of the analog quantity signals is kept equal to the voltage of the sampling signal data, the constant-current discharge circuit is ensured to output stable discharge current, and the precision of detecting the internal resistance of the storage battery by the internal resistance detection circuitof the storage battery is improved.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to a storage battery internal resistance detection circuit and a method thereof. Background technique [0002] After one or several batteries in the battery pack are aging, the capacity of the aging battery becomes smaller and the resistance becomes larger. When the charger charges the battery pack, it is easy to continue to output a small current for charging the battery pack after the aging battery is fully charged. At this time It is difficult to fully charge the remaining batteries in good condition with low current. After repeated float charge and discharge vicious cycles, the overall capacity of the battery continues to decline, which greatly reduces the performance of the battery. [0003] The internal resistance of the battery is the parameter that can most intuitively reflect the internal state of the battery pack. By detecting the internal resistance of the batte...

AI Technical Summary

Problems solved by technology

However, the conventional battery internal resistance detection mostly uses simple voltammetry measurement. In actual measurement, it is found that there are charging and discharging between the battery packs at the same time. The precision is too low

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